This disclosure relates to a method of manufacturing integral bladed rotors for a gas turbine engine.
Gas turbine engines include a turbine rotor mounted on a shaft. The rotor includes multiple turbine blades supported on its periphery. In one type of arrangement, each blade is separately secured to the rotor. In another type of arrangement, the blades are integral with the rotor. The turbine blades and rotor are machined from a blank, which is constructed from a nickel material, for example.
A significant amount of material is machined from the blank to provide the numerous blades when manufacturing integral bladed rotors. One machining approach employs a super abrasive machining method, which uses a cubic boron nitride cutting disc. The cutting disc, or cutter, is used to cut a slot between the locations at which the blades will be provided on the blank extending from an outer perimeter of the blank to an inner perimeter of the blank. Next, a smaller abrasive cutter is used in the initial slot to provide a rough approximation of the blade contours. The smaller cutters are used to produce discreet cuts in the blank. The smaller cutter is fragile and difficult to cool. Subsequent to using the smaller cutter, a semi-finish cutter and then a finish cutter are used to provide the final blade contours.
The rough cutting process used to provide the rough blade contours is long, labor intensive and costly. Generally, multiple tool changes are required when the small cutter breaks. What is needed is a faster, more reliable and less expensive machining method to provide the rough blade contours.